The present invention generally relates to spray washing systems and more particularly to container washing apparatus including one or more liquid supply lines, each having a series of spray nozzles.
Conventional container washing systems utilize a large quantity of spray nozzles, often several hundreds or thousands in number, extending from sides of risers or supply lines. Supply lines are mounted both above and below a liquid permeable conveyor formed of an open mesh material such as plastic or stainless steel. The conveyor moves the containers past the spray nozzles. In such container washing systems, the containers may move along a path often stretching over 100 feet long and pass many different washing, rinsing and treating stations of the system. The spray nozzles at washing and rinsing stations are usually of the type that discharge an elongated, narrow fan spray toward a desired location. Pressurized fan sprays are very effective for washing operations. When oriented correctly and precisely, the use of fan sprays results in full efficient spray coverage and prevents cans from being dislodged or knocked over on the conveyor. The fluid sprays above and below the cans must be precisely aligned in order to prevent the cans from being knocked over and to guarantee proper spray coverage and consequently clean cans.
Maintenance of such systems is extremely difficult. Generally, the sprays extend from the risers at 90.degree. and thus, angled fittings are required. Such angled fittings are disclosed, for example, in U.S. Pat. No. 5,564,448. This patent discloses an apparatus adapted to permit easy removal of the nozzles from the risers. However, the risers are all formed from metal, generally eight to ten feet long. Removal of the risers for maintenance purposes requires at least two or three individuals. It would be desirable to replace the risers with plastic to permit cleaning. Further plastic is corrosion resistant and therefore has a longer life and is less likely to foul. Unfortunately, container washing systems operate at relatively high temperatures and the force of the spray in combination with the high temperature softening of the plastic would cause the risers to move excessively. This in turn would cause the fluid sprays to be misaligned and in turn, knocking the cans over as they pass the washing apparatus.